In semiconductor devices such as IGBTs (Insulated Gate Bipolar Transistors), there is a structure in which an interlayer insulating film is provided on a semiconductor layer and an emitter electrode is provided on the interlayer insulating film. The emitter electrode and a semiconductor region are electrically connected via a contact region including metal and piercing through the interlayer insulating film.
However, when the volume of the contact region piercing through the interlayer insulating film is small, the volume of the interlayer insulating film on the semiconductor region relatively increases. Here, the thermal resistance of the interlayer insulating film is high compared to that of metal constituting the emitter electrode and the contact region.
Hence, when the volume of the interlayer insulating film on the semiconductor layer is large and the volume of the contact region is small, heat generated in the semiconductor layer is less likely to dissipate to the emitter electrode side. Hence, in the semiconductor layer, a breakdown due to heat, a device breakdown that the emitter electrode above the semiconductor layer melts, or the like may occur.